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cc ep te d A rt ic le This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this... more
cc ep te d A rt ic le This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/1365-2745.12195 This article is protected by copyright. All rights reserved.
on the distribution of surface sediment diatoms in an upland loch, Scotland
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Project co-funded by the European Commission within the Sixth Framework Programme (2002-2006) Dissemination Level (tick appropriate box) PU Public PP Restricted to other programme participants (including the Commission Services) RE... more
Project co-funded by the European Commission within the Sixth Framework Programme (2002-2006) Dissemination Level (tick appropriate box) PU Public PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission Services) CO Confidential, only for members of the consortium (including the Commission Services)
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Spatial and temporal variability in periphytic diatom communities: Palaeoecological significance in an acidified lake. VJ Jones, RJ Flower 1986. Spatial and temporal variations in the epipsammic and epilithic diatom communities ...
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In a review of work on 10 of the very numerous lakes of the English Lake District work which involved co-operation between palaeolimnologists from different disciplines and between palaeoand neolimnologists the questions asked by the... more
In a review of work on 10 of the very numerous lakes of the English Lake District work which involved co-operation between palaeolimnologists from different disciplines and between palaeoand neolimnologists the questions asked by the researchers are listed and it is shown which kind of lake has provided constructive answers. Complete and conformable sediment profiles covering the last ca 14000 years are found in these lakes, but no single profile is optimal for study of the whole period. Knowledge of the pattern of sediment accumulation is necessary before the record in microfossils and changing sediment composition can be interpreted with confidence. The demonstration that the sedimentsource material of these open lakes must have been largely allochthonous established the importance of the sediment column as a record of changes through time in the composition and stability of the soils of each catchment. These changes illustrate the influence of: 1. Climatic changes, from glacial to temperate interstadial followed by renewed glaciation (Younger Dryas) and then by a long temperate (postglacial) state, during which changes in stream run-off and in the pattern of deposition in lakes indicate changes in precipitation and wind-induced turbulence. 11. Processes of pedogenesis, determining the composition of sediment-source material. iii. Changes in aquatic and terrestrial biota in response to climatic changes interacting with biological processes; the major changes which coincide with changing land use by man over 5000 years, and the more recent changes associated with the dates for human discharges into lakes and the deposition of airborne pollutants.
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Research Interests: Immunology, Multiple sclerosis, Biology, Medicine, Neuroimmunology, and 15 moreWestern blotting, Humans, Central Nervous System, Cadaver, Aged, Middle Aged, White matter, Adult, phospholipases A2, Densitometry, Calcium Binding Proteins, Reference Values, Neurosciences, Tissue distribution, and Annexins
I first heard of Ed Deevey in 1950, when I was a beginning Ph.D. student at Yale. I came from a three-person biology department whose minuscule library did not include the American Journal of Science, in which Ed had published his most... more
I first heard of Ed Deevey in 1950, when I was a beginning Ph.D. student at Yale. I came from a three-person biology department whose minuscule library did not include the American Journal of Science, in which Ed had published his most important work. I had, however, been poking around the lakes and bogs of Nova Scotia for five years and was full of half-formed ideas about paleolimnology, climatic change, and the relevance of past climate to the modern distribution of plants and animals. I was chagrined to find a man I had never heard of, an American at that, who’d had all the same ideas ten years before, formulated them more clearly and carried out the work with an ingenuity and completeness beyond my aspirations. For a few weeks I was afraid to read another Deevey paper, and when the man himself returned from Yucatan I became his first graduate student.
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Algal diversity in aquatic environments can help assess the health status of ecosystems, provide information about invasions of new species and inform species diversity changes according to environmental conditions. An algal diversity... more
Algal diversity in aquatic environments can help assess the health status of ecosystems, provide information about invasions of new species and inform species diversity changes according to environmental conditions. An algal diversity survey (2016–19) of Nador Lagoon (northern Morocco) revealed the presence for the first time of the brown alga Cystoseira aurantia. Since 2015 this alga has been found in high abundance in the northwestern part of the lagoon, mainly around Attalayoun and Nador City. The thalli of larger specimens reached 60 cm in length, and all plants present were free-floating. The species was collected from the water surface to depths not exceeding 2 cm. Floating patches were usually found suspended above sandy and muddy substrates. Increased abundance of this species in the lagoon corresponds with new physico-chemical conditions and ecological parameters, principally resulting from increased water ventilation and improved water quality since 2012. The new communiti...
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[Figure: see text].
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Research Interests: Biology, Ecology, Biological Sciences, Environmental Sciences, Diatom, and 4 moreGenus, Estuary, Subtropics, and Taxon
The genus Amphorotia Williams & Reid (2006) was established to accommodate a group of diatoms formerly allocated to Eunotia Ehrenberg. The new genus was shown to display a distinct biogeographical distribution. To increase the... more
The genus Amphorotia Williams & Reid (2006) was established to accommodate a group of diatoms formerly allocated to Eunotia Ehrenberg. The new genus was shown to display a distinct biogeographical distribution. To increase the knowledge of this genus, especially in China, a taxonomic investigation of Amphorotia in the Pearl River delta area was undertaken using borehole materials. This paper reports and describes specimens of an uncommon species of Amphorotia extracted from sediment samples using a special concentration technique. Morphological data derived from both light (LM) and scanning electron microscopy (SEM) are used to characterise the specimens. Based on these observations, an emended description of a species formerly reported from the same region, Amphorotia curvata Williams & Reid, is provided and its neotype is established. The new Pearl River specimens are all attributed to A. curvata and this species is compared to other Amphorotia species from China, Southeast Asia and Lake Baikal. It is similar to the Siberian taxon Amphorotia lacusbaikali (Skvortzov) Williams & Reid when observed with LM, but can be distinguished by ultrastructural details (SEM). Amphorotia is clearly monophyletic and the new features of A. curvata are used to suggest links with Amphorotia species from East Asian regions.
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[Yang, Hong; Xie, Ping; Ni, Leyi] Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol China, Donghu Expt Stn Lake Ecosyst, Wuhan 430072, Peoples R China; [Yang, Hong] Univ Southampton, Southampton SO17 1BJ,... more
[Yang, Hong; Xie, Ping; Ni, Leyi] Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol China, Donghu Expt Stn Lake Ecosyst, Wuhan 430072, Peoples R China; [Yang, Hong] Univ Southampton, Southampton SO17 1BJ, Hants, England; [Flower, Roger J.] UCL, Dept Geog, Environm Change Res Ctr, London WC1E 6BT, England
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Responses of four lakes to post-1970 changes in acid deposition, afforestation and liming are examined by using water quality measurements and palaeolimnological analysis. pH and non-marine sulphate concentrations at an undisturbed site... more
Responses of four lakes to post-1970 changes in acid deposition, afforestation and liming are examined by using water quality measurements and palaeolimnological analysis. pH and non-marine sulphate concentrations at an undisturbed site approximately parallel trends in precipitation and indicate that lake water quality has improved since the late-1970s as atmospheric S emissions have declined. Carbonaceous particle contamination of the lake also declines in this period but diatom analysis shows that the ecological response to these changes are as yet small. However, at a similar but recently afforested site, major changes in sedimentary diatoms have occurred and we argue that fertilizer leaching is the cause. At the two limed sites the diatom response is proportional to liming intensity but at neither site has the pre-acidification diatom flora been re-established.
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ABSTRACT We assess the recovery of UK lakes from acidification using the combined data from sediment cores and sediment traps to track changes in diatom assemblages in 11 UK upland lakes from pre-acidification times (prior to ca. 1850 AD)... more
ABSTRACT We assess the recovery of UK lakes from acidification using the combined data from sediment cores and sediment traps to track changes in diatom assemblages in 11 UK upland lakes from pre-acidification times (prior to ca. 1850 AD) to the present (2008 AD). We projected the data into a Principal Component Analysis (PCA) of diatom assemblage data from 121 low-alkalinity lakes in the UK to show how the floristic composition of the core and trap diatom assemblages for each site has changed through time. The results show that the degree of recovery from acidification varies amongst sites but in all cases its extent is limited when compared with the pre-acidification reference. In most cases the recovery, although usually slight, is characterised by a decline in acid tolerant taxa and a return towards taxa that occurred previously at each respective site. In a few cases, however, the floristic composition of recent samples is different from those that occurred during and before the acidification phase. The reasons for this are not yet clear but it is possible that nutrient enrichment from atmospheric N deposition and/or climate change is beginning to play a role in driving water quality as acidity decreases. More generally the results show that annually recovered samples from sediment traps can be successfully combined with sediment core data to provide a continuous record of environmental change in lake systems, and that diatoms collected in sediment traps can be used to provide a very powerful lake monitoring tool.
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ABSTRACT A new species of Achnanthes, A. scotica, is described from Lochnagar in the Cairngorm Mountains, Scotland. Three new varieties, A. altaica v. minor, A. austriaca v. minor, and A. austriaca v. alpina and one new form, A.... more
ABSTRACT A new species of Achnanthes, A. scotica, is described from Lochnagar in the Cairngorm Mountains, Scotland. Three new varieties, A. altaica v. minor, A. austriaca v. minor, and A. austriaca v. alpina and one new form, A. marginulata f. major, are also described from sites in the Cairngorms and elsewhere. Modern and fossil distributions of these taxa in acid upland oligotrophic UK lakes are evaluated.
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Mackay, AW and Flower, RJ and Battarbee, RW (1994) Further high resolution analyses of surface sediment cores taken from Lake Baikal. Second Year. Report to the Leverhulme Trust on Grant F.134 AZ. (ECRC Research Report 18 ). Environmental... more
Mackay, AW and Flower, RJ and Battarbee, RW (1994) Further high resolution analyses of surface sediment cores taken from Lake Baikal. Second Year. Report to the Leverhulme Trust on Grant F.134 AZ. (ECRC Research Report 18 ). Environmental Change Research Centre: London. ... Full text not available from this repository. ... Further high resolution analyses of surface sediment cores taken from Lake Baikal. Second Year. Report to the Leverhulme Trust on Grant F.134 AZ.
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Mackay, AW and Flower, RJ and Battarbee, RW (1996) Stratigraphic evidence of environmental change in Lake Baikal, associated with recent changes in climate. Final Report to the Leverhulme Trust on Grant No. F.134 AZ. (ECRC Research Report... more
Mackay, AW and Flower, RJ and Battarbee, RW (1996) Stratigraphic evidence of environmental change in Lake Baikal, associated with recent changes in climate. Final Report to the Leverhulme Trust on Grant No. F.134 AZ. (ECRC Research Report 19 ). Environmental Change Research Centre: London. ... Full text not available from this repository. ... Stratigraphic evidence of environmental change in Lake Baikal, associated with recent changes in climate. Final Report to the Leverhulme Trust on Grant No. F.134 AZ.
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We explore possible quantitative relationships between diatom species and environmental data for Lake Baikal using multivariate techniques. Our approach differs from published studies in other regions (on training sets and transfer... more
We explore possible quantitative relationships between diatom species and environmental data for Lake Baikal using multivariate techniques. Our approach differs from published studies in other regions (on training sets and transfer functions) because (1) although only one lake is examined, we use the internal lake gradients rather than gradients among lakes and (2) the majority of the dominant diatom taxa are endemic. Canonical correspondence analysis on 93 surface sediment diatom assemblages reveals that major taxa show distinct relationships with measured environmental variables. Five significant variables were identified: snow thickness on ice (which accumulates on the frozen lake surface between January and April/May), water depth, suspended matter, annual solar radiation, and mean July temperature of surface waters. The strongest relationship is with snow thickness, which influences light levels in the water below the ice. A diatom-based inference model has been developed to pr...
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A morphological study of Scyliorhinus canicula in Algerian coastal waters was undertaken using biometric measurements. Size variation of males and females was determined and the state of sexual development was assessed for functional... more
A morphological study of Scyliorhinus canicula in Algerian coastal waters was undertaken using biometric measurements. Size variation of males and females was determined and the state of sexual development was assessed for functional significance. The total monthly sampling over one year comprised 209 males and 251 females. All specimens were collected from commercial landings of the Oran fishery. Total length of fish varied between 28.5 and 50 cm for females and 28.5 to 55 cm for males. Females showed no distinct morphological features of maturity but some changes in ovary and oviduct structure were observed. Mature males were easily recognizable by morphological changes in the urogenital tract. Adult testes are in an elongated mass form. The right testis is typically more developed and heavier than the left. Sexual maturity is reached after 5 years for both males and females when they are around 38 cm in total length and 290 g in weight. The maximum total length recorded was 55 cm...
Population parameters of the Atlantic horse mackerel Trachurus trachurus were investigated using size-at-age data derived from regular monthly samples comprising 962 individuals (488 males, 358 females and 116 undetermined). Samples were... more
Population parameters of the Atlantic horse mackerel Trachurus trachurus were investigated using size-at-age data derived from regular monthly samples comprising 962 individuals (488 males, 358 females and 116 undetermined). Samples were collected from the population living near the North Atlantic Moroccan coast (Larache area) between June 2005 and November 2006. The growth study was based on the interpretation of growth rings observable on 687 otoliths (Sagitta). The otoliths preserved two annual growth rings, one opaque and the other hyaline. The opaque ring is formed mainly in spring and summer, while the hyaline is formed in autumn and winter. Total fish length varied between 12.8 to 38.4 cm and total weight from 15.0 to 528.7 g; the calculated length-weight relationship was W = 0.005 L3.171. Parameters estimated by the Von Bertalanffy growth equation (using all captured individuals) were L∞ = 44.67 cm, K = 0.14 year-1 and t0 = -0.46 year. The maximum observed age was 9 years. R...
The diatom genera encountered in this study.
A figure showing the species–genus richness relationships.